1. The Field of the Invention
The present invention relates generally to trailer and towing safety devices, and more particularly, but not necessarily entirely, to trailer automatic braking devices that initiate braking when a trailer becomes separated from its tow vehicle.
2. Description of Related Art
The two most common trailer brake systems are electrical and hydraulic both have safety brake actuator systems to apply the brakes in a case where the trailer becomes separated from the tow vehicle. The electrical style breakaway system is made up of a power connection box attached to the trailer frame. This power connection box is typically equipped with electrical contacts separated by a non-conductive pull pin. This pull pin is removable and connected to a cable (typically 4-6 feet long). One end of this cable is attached to the pull pin while the other end is to be attached to the tow vehicle. In case the tow vehicle and trailer become separated while moving, the cable attached to the tow vehicle will pull the non-conductive pull pin out of the power connection box allowing the electrical contacts to contact each other, thus sending an electrical charge to the trailer brakes. The desired effect is that the trailer brakes stop the now detached trailer before it damages itself or another object.
A switch box (would be mounted to the trailer frame) cable is attached to pull pin/plunger that is removable from a switch box. A loop on the other end of cable is to be attached to the tow vehicle. A switch box and connective cable is used with bumper pull style trailers and is also used with Gooseneck and fifth wheel style trailers.
The hydraulic breakaway system is part of the hydraulic brake system which is typically integrated into the trailer coupler or forward frame section of a trailer equipped with hydraulic wheel/axle brakes. This brake actuator has a safety lever protruding from the actuator and generally in a rearward facing orientation. Attached to this lever is a cable or chain (typically 3-6 feet long). The free end of the cable is attached to the tow vehicle. In a situation where the tow vehicle and trailer become separated while moving, the tow vehicle will pull away from the trailer thus pulling the protruding safety brake activation lever into a forward orientation-which causes the inner portion of the safety lever to compress the master cylinder which compresses the hydraulic brake fluid and sends compressed brake fluid to the trailer brakes. The desired effect is that the trailer brakes stop the now detached trailer before it damages itself or another object.
A surge brake style coupler for straight tongue trailers with emergency breakaway actuator levers protruding from the top also use a similar system. One end of cable is attached to the lever and the other has a hook or loop to attach to the tow vehicle. Like the above systems, this brake actuator has a safety lever protruding from the actuator and generally in a rearward facing orientation. Attached to this lever is a cable or chain (typically 3-6 feet long). The free end of the cable is attached to the tow vehicle. In a situation where the tow vehicle and trailer become separated while moving the tow vehicle will pull away from the trailer thus pulling the protruding safety lever into an activated orientation-which causes the inner portion of the safety lever to activate the surge mechanism. The desired effect is that the trailer brakes stop the now detached trailer before it damages itself or another object.
FIG. 1 is illustrative of a trailer 10 to tow vehicle 12 union. Typically, a trailer 10 is attached for towing to a tow vehicle 12 through union assembly 14.
FIG. 2 is illustrative of a trailer 10 to tow vehicle 12 connection that has become disassociated because the union assembly 14 as come apart as shown by the bracket.
FIG. 3 is illustrative of a chain 18 used in a breakaway switching mechanism wherein the trailer 10 is connected to the tow vehicle 12. The switching mechanism comprises a switch 16, a pin 17, a chain 18 and a tow vehicle attachment 20.
FIG. 4 is illustrative of a chain 18 used in a breakaway switching mechanism wherein the trailer 10 is disconnected from the tow vehicle 12 and the chain 18 has been pulled taught.
FIG. 5 is illustrative of a chain 18 used in a breakaway switching mechanism wherein the trailer 10 is disconnected from the tow vehicle 12 and the chain has pulled the pin 17 from the safety switch 16;
FIG. 6 is illustrative of a cable 28 used in a breakaway switching mechanism wherein the trailer 10 is connected to the tow vehicle 12 and the cable 28 drags on the ground. The portion of the cable that drags is denoted by bracket D.
Despite the advantages of known safety systems and apparatus, improvements are still being sought. For example, many of the current devices require extra user effort to address problems of dragging cables and chains. For many years the safety braking systems on trailers have been equipped with cable typically 3-6 feet long or occasionally small chain. There must be slack in this cable to allow articulating movement between the tow vehicle and trailer without actuating/locking up the trailer brakes in a normal towing situation. The problem with this design is that the safety cable often hangs down near the road surface and in a turn or when going over bumps or rough terrain the cable comes into contact with the road while the vehicles are moving. This contact frays the cable, often to the point that the cable completely separates into two pieces. A cable that is in two pieces or frayed to near separation and weakened cannot perform its intended safety function of actuating the brakes. Further, it is a safety hazard to the operator as the fragmented cable wires often gouge into the hand while trying to hook up the system.
The solution up to this time has been to sell the trailer user a replacement cable or completely new electrical switch systems. Little effort has been made to protect the cable from dragging in the first place. While this problem of the cable dragging is specific to bumper pull trailers, the same electrical actuator is used on gooseneck and fifth wheel style trailers. In these type of trailers the cable doesn't risk dragging on the ground as the cable attaches in the bed of the truck, they do however risk being caught on cargo or the hitch mechanism, potentially locking up the trailer brakes while in a normal, coupled, towing situation.
The prior art is thus characterized by several disadvantages that are addressed by the present invention. The present invention minimizes, and in some aspects eliminates, the above-mentioned failures, and other problems, by utilizing the methods and structural features described herein.
The features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by the practice of the invention without undue experimentation. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims.